Single-Photon Emission Computed Tomographic Myocardial ...

Single-Photon Emission Computed Tomographic Myocardial Perfusion Imaging in Patients With Mitral Valve Prolapse ¨ zkan, MD, Cihangir Kaymaz, MD, Hakan Dinc¸kal, MD, Cevat Kirma, MD, Mehmet O ¨ Nihal Ozdemir, MD, ˙Ilyas Akdemir, MD, Kenan So ¨ nmez, MD, Bu¨lent Mutlu, MD, ¨ nsel, MD Vedat Sansoy, MD, and C etin O ¸ everal studies have been undertaken using myocardial perfusion imaging to detect myocardial S ischemia in patients with mitral valve prolapse (MVP).1–9 Controversial results were obtained in patients with MVP without coronary artery disease.1–11 Moreover, these previous studies have been performed mostly in the 1970s using planar myocardial perfusion imaging with thallium-201 (Tl-201).1– 8 Recently, it was shown that single-photon emission computed tomography has better ability to allow visual analysis of all coronary regions in the diagnosis of coronary artery disease than planar imaging.12–14 This study was designed to assess myocardial perfusion imaging using single-photon emission computed tomographic (SPECT) analysis and recently established echocardiographic criteria for MVP. •••

Seventy-two consecutive patients (39 women and 33 men, aged 31 to 63 years [mean 49 ⫾ 10]) with MVP were prospectively enrolled in this study. Twenty patients had no chest pain, whereas 51 patients described atypical chest pain and 1 patient described chest pain typical for angina pectoris. At baseline examination, auscultation revealed a midsystolic click alone in 6 (8%), midsystolic click and late systolic murmur in 16 (22%), midsystolic click and midsystolic murmur in 2 (3%), a late systolic murmur alone in 27 (37.5%), and a holosystolic murmur in 20 (28%) patients. One patient (1.5%) had MVP that was silent to auscultation. Patient characteristics and diagnostic methods were presented in Table I. All patients underwent exercise or dipyridamole technetium-99m sestamibi (MIBI) or Tl-201 tomography. Patients with positive exercise electrocardiography or positive myocardial perfusion scintigraphy and those aged ⬎40 years who were considered for mitral valve surgery underwent coronary angiography. Transthoracic echocardiography was performed using a Vingmed CFM 800 system (Horten, Norway) with a 3.25-MHz transducer. The images were recorded on VHS videotape, and 2 experienced observers without knowledge of clinical data independently analyzed the echocardiographic findings. In case of disagreement, the final decision was reached by conFrom the Cardiology Clinic, Kos¸uyolu Heart and Research Hospital, Istanbul; and Cerrahpas¸a Medical Faculty, Istanbul University, Istan¨ zkan’s address is: Cardiology Clinic, Kos¸uyolu bul, Turkey. Dr. O Heart and Research Hospital, Kadiko¨y, 81020, Istanbul, Turkey. Manuscript received July 8, 1999; revised manuscript received September 17, 1999, and accepted September 20.

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©2000 by Excerpta Medica, Inc. All rights reserved. The American Journal of Cardiology Vol. 85 February 15, 2000

TABLE I Patient Characteristics and Diagnostic Methods Variable Mean age Chest pain Atypical Typical Resting ST/T abnormalities Stress test Treadmill Dipyridamole Radiopharmaceutical agent Tl-201 Tc-99m sestamibi

Total (n ⫽ 72)

Women (n ⫽ 39)

Men (n ⫽ 33)

49 ⫾ 10

48 ⫾ 10

49 ⫾ 9

51 (71%) 1 (1%) 16 (22%)

30 0 10

21 1 6

63 (88%) 9 (12.5%)

36 3

27 6

25 (35%) 47 (65%)

19 20

6 27

Tc ⫽ technetium; Tl ⫽ thallium.

sensus. Using the echocardiographic criteria proposed by Marks et al,15 MVP was defined as systolic displacement of the thick and redundant valve leaflet(s) above the plane of the mitral annulus (ⱖ5 mm ) to the left atrium in the parasternal long-axis and apical long-axis views. The severity of mitral regurgitation was determined according to generally accepted criteria.16 A mild, moderate, and severe regurgitation was diagnosed when regurgitant jet area was ⬍4 cm2, 4 to 8 cm2, and ⬎8 cm2, respectively. Thirty-two patients (44%) had moderate to severe mitral regurgitation, whereas the remaining 40 patients (56%) had trace to mild mitral regurgitation. Chordal rupture was detected in 8 patients (11%). Sixty-three patients (88%) underwent a symptomlimited treadmill exercise test using standard Bruce protocol. A 12-lead electrocardiogram and arterial blood pressure were continuously monitored and recorded at baseline and at 1-minute intervals during exercise and recovery. End points of the test were severe chest pain, horizontal or downsloping ST depression ⱖ3 mm 80 ms after the J point, fatigue, hypotension, and serious arrhythmia. An abnormal exercise electrocardiogram was defined as ⱖ1 mm horizontal or downslopping ST-segment depression occurring 80 ms after the J point in ⱖ1 lead(s). Tl-201 and MIBI were used in 25 and 47 patients, respectively (Table I). At peak exercise, 2.5 to 3.0 mCi of Tl-201 was administered intravenously and patients were encouraged to continue exercising for 1 to 2 minutes. SPECT imaging was performed as soon as possible after the end of exercise and again 3 to 4 0002-9149/00/$–see front matter PII S0002-9149(99)00786-9

Coronary angiography and cardiac catheterization were performed Moderate to Mild or in 15 patients who subsequently unSevere MR No MR derwent mitral valve surgery and in 5 Total (n ⫽ 32) (n ⫽ 40) patients with a positive treadmill Exercise parameters stress test. Selective coronary anMean duration (min) 6.9 ⫾ 2 6.5 ⫾ 2.0 7.1 ⫾ 1.85 giography was performed in multiple METs 8.7 ⫾ 2.0 8.4 ⫾ 2.1 8.8 ⫾ 2.0 views using the Judkins technique. Maximal heart rate 170 ⫾ 15 175 ⫾ 17 167 ⫾ 14 Coronary stenosis was considered (beats/min) Double product 32,911 ⫾ 7,575 34,339 ⫾ 8,894 31,971 ⫾ 6,525 significant when the vessel diameter Chest pain was narrowed ⬎50% in the coronary Atypical 6 (8%) 3 (9%) 3 (7%) arteries. Typical 0 0 0 A chi-square test and Student’s t Ventricular premature 15 (21%)* 10 (31%)* 5 (13%)* test were used for the comparison of contraction Paired ventricular premature 4 (5%)* 4 (13%)* 0* discrete and continuous variables, recontraction spectively. A p value ⬍0.05 was Positive exercise ECG 5 (8%) 4 (16%) 1 (3%) considered significant. Normal SPECT 72 (100%) 32 (100%) 40 (100%) On the rest electrocardiogram, Normal coronary 15/15 (100%) 11 4 arteriography nonspecific ST-T-segment variations Left ventricular diameters were observed in 16 patients (23%). (cm) No patient had any left ventricular End-systolic diameter 3.25 ⫾ 0.5† 3.5 ⫾ 0.5† 3.05 ⫾ 0.45† † † † hypertrophy on the electrocardioEnd-diastolic diameter 5.0 ⫾ 0.7 5.5 ⫾ 0.6 4.7 ⫾ 0.44 gram. The exercise electrocardiogra*p ⬍0.05; †p ⬍0.001. phy was found to be abnormal in 5 ECG ⫽ electrocardiogram; METs ⫽ metabolic equivalents; MR ⫽ mitral regurgitation. patients (8%). Exercise test results are summarized in Table II. Mean duration of the exercise test was hours after the Tl-201 injection. When MIBI was 6.9 ⫾ 2.0 minutes. Metabolic equivalents was 8.7 ⫾ used, a rest/stress protocol was performed. Sixty min- 2.0 and and maximum heart rate 170 ⫾ 15 beats/min, utes after 7 mCi of MIBI injection, rest images were respectively. During the treadmill stress test, atypical acquired, 20 mCi was injected at peak exercise, and chest pain was produced in 6 patients (8%), whereas postexercise images were acquired 60 minutes later. no patient experienced typical anginal chest pain. All patients had a 4-minute intravenous infusion of Atypical chest pain was observed in 3 patients (9%) 0.56 mg/kg of dipyridamole, 2 to 3 mCi of Tl-201 was with severe mitral regurgitation, and in 3 (7%) without administered, and SPECT acquisition began 3 minutes or mild mitral regurgitation (p ⬎0.05). Paroxysmal later. Redistribution images were recorded 3 to 4 supraventricular tachycardia, atrial flutter or fibrillation, and ventricular tachycardia were not induced hours after Tl-201 injection. SPECT imaging was performed with a single-head during exercise test. Single and paired stress-induced rotating gamma camera (SOPHA DS7, Buc, France), ventricular premature contractions were observed in equipped with a low-energy, all-purpose collimator 15 (21%) and 4 (5%) patients, respectively. Frequency interfaced to a dedicated computer. Patients were of exercise-induced single ventricular premature conplaced in the supine position and 32 projections were tractions (31% and 13%, p ⬍0.05), and paired venobtained, 40 seconds each, through a 180° orbit be- tricular premature contraction (13% and 0%, p ⬍0.05) ginning in a 45° right anterior oblique position and were significantly higher in patients with severe mitral ending in a 45° left posterior oblique position. Images regurgitation than in patients with mild or absent were stored in a 64 ⫻ 64 byte matrix. Tomographic mitral regurgitation. On echocardiography, left venreconstruction was performed with a filtered back- tricular systolic and diastolic diameters were signifiprojection algorithm and a Hamming Hann filter for cantly different between patients with moderate to Tl-201 and Butterworth filter for MIBI. The transaxial severe mitral regurgitation and patients with mild or slices were realigned along the heart axis, and the no mitral regurgitation (p ⬍0.001) (Table II). No significant perfusion defect related to ischemia short-axis, vertical, and horizontal long-axis slices were obtained. For the purpose of the study, 3 short- was detected in any patient with MVP in this study axis (base, mid-, and apical planes) and 1 vertical group. Five patients with an abnormal exercise eleclong-axis (midsagittal slice) view were used for anal- trocardiogram and a normal perfusion scintigraphy ysis. Qualitative interpretation of the scintigraphic im- and 15 patients considered for valve replacement unages was performed independently by 2 experienced derwent coronary angiography; no significant coronuclear medicine physicians without knowledge of the nary artery disease was found in any of these patients. echocardiographic characteristics of the patients. Isch••• emia was defined as a perfusion defect during exercise The present study demonstrates that myocardial that partially or totally resolved at rest in at least 2 perfusion scintigraphy is normal in patients with MVP contiguous segments in 3 successive slices. In case of and chest discomfort or arrhythmia. We did not perdisagreement a decision was reached by consensus. form coronary angiography in all patients with a norTABLE II Summary of Stress Tests, SPECT, and Coronary Angiography

BRIEF REPORTS

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mal myocardial perfusion scintigraphy; however, because the major diagnostic problem is not the low sensitivity but the low specificity, we believe that this study addresses the issue properly. Certainly, normal perfusion scintigraphy does not exclude the possibility of focal myocardial ischemia beyond the resolution limits of current techniques.12–14 Because false-positive exercise electrocardiography has been reported to be more common in this entity, myocardial perfusion scintigraphy may the preferred method in these patients.1–9 In conclusion, this study indicates that patients with MVP and angina-like chest pain may benefit from a Tl-201 or MIBI exercise or pharmacologic stress testing. The resulting normal study reassures the physician and the patient that the chest pain is not the result of coronary artery disease. 1. McLaughlin P, Huckell V, Staniloff H, Buda A, Feiglin D, Wigle D, Morch J. Exercise induced chest pain, myocardial perfusion and stress electrocardiography in patients with mitral valve prolapse. Circulation 1977; 56(suppl III):III–216. 2. Padmanabham V, Margouleff D, Binder A, Morrison J, Pizzarello R, Gulotta S. Thallium-201 myocardial imaging during exercise in mitral valve prolapse. Circulation 1977;56(suppl III): III–216. 3. Massie B, Botvinick EH, Shames D, Taradash M, Werner J, Schiller N. Myocardial perfusion scintigraphy in patients with mitral valve prolapse. Its advantage over stress electrocardiography in diagnosing associated coronary artery disease and its implications for the etiology of chest pain. Circulation 1978;57:9 –26. 4. Klein GJ, Kostuk WJ, Boughner DR, Chamberlain MJ. Stress myocardial imaging in mitral leaflet prolapse syndrome. Am J Cardiol 1978;42:746 –750.

5. Tresch DD, Soi SS, Siegel R, Love M, Keelan MH. Mitral valve prolapse— evidence for a myocardial perfusion abnormality. Am J Cardiol 1978;41(suppl): 441. 6. Gaffney FA, Wohl AJ, Blomquist CG, Parkey RW, Willerson JT. Thallium201 myocardial perfusion studies in patients with the mitral valve prolapse syndrome. Am J Med 1978;64:21–26. 7. Greenspan M, Iskandrian AS, Mintz GS, Croll MN, Segal BL, Kimbiris D, Bemis CE. Exercise myocardial scintigraphy with 201-thallium. Use in patients with mitral valve prolapse without associated coronary artery disease. Chest 1980;77:47–52. 8. Butman S, Chandraratna PA, Milne N, Olson H, Lyons K, Aronow WS. Stress myocardial imaging in patients with mitral valve prolapse: evidence of perfusion abnormality. Cathet Cardiovasc Diagn 1982;8:243–252. 9. Voth E, Schicha H, Tebbe U, Neumann P, Emrich D. Fatty acid metabolism in symptomatic patients with mitral valve prolapse but without coronary artery disease— comparison with 201 Tl myocardial perfusion scintigraphy. Nuklearmedizin 1987:26:172–176. 10. Sakuma T, Kakihana M, Togo T, Matsuda M, Ogawa T, Sugishita Y, Ito I, Kurusu T. Mitral valve prolapse syndrome with coronary artery spasm: a possible cause of recurrent ventricular tachyarrhythmia. Clin Cardiol 1985;8:306 –309. 11. Lobstein HP, Horwitz LD, Curry GC, Mullins CB. Electrocardiographic abnormalities and coronary arteriograms in the mitral click-murmur syndrome. N Engl J Med 1973;289:127–131. 12. Verani MS, Marcus ML, Razzak MA, Ehrhardt JC. Sensitivity and specificity of thallium-201 perfusion scintigrams under exercise and the diagnosis of coronary artery disease. J Nucl Med 1978;19:773–778. 13. Beller GA. Myocardial perfusion imaging with thallium-201. In: Marcus ML, Schelbert HR, Skorton DJ, Wolf GL, eds. Cardiac Imaging. Philadelphia: WB Saunders, 1991:1057–1067. 14. Beller GA. Clinical Nuclear Cardiology. Philadelphia: WB Saunders, 1995: 82–136. 15. Marks AR, Choong CY, Chir MB, Sanfilippo J, Weyman AE. Identification of high risk and low risk subgroups of patients with mitral valve prolapse. N Engl J Med 1989;320:1031–1036. 16. Helmcke F, Nanda N, Hsiung M, Soto B, Adey CK, Goyal RG, Gatewood RP. Color Doppler assessment of mitral regurgitation with ortogonal planes. Circulation 1987;75:175–183.

Comparison of Central Venous and Inferior Vena Caval Pressures John T. Walsh, MD, David J.R. Hildick-Smith, MD, Stuart A. Newell, Martin D. Lowe, MD, Duwarakan K. Satchithananda, MD, and Leonard M. Shapiro, easurement of central venous pressure (CVP) is often required in critically ill patients. ConvenM tionally, venous access is preferred via the internal jugular or subclavian vein with measurement of CVP in the superior vena cava (SVC) above the right atrium. However, this approach is potentially hazardous, risking carotid artery puncture, pneumothorax, and neurologic damage.1–3 Central venous access may also be achieved via the femoral vein (FV).4,5 CVP can then be measured by positioning the catheter in the right atrium or SVC, but long-term placement within or across the right atrium is associated with dysrhythmias, atrial thrombus, and cardiac rupture.6 – 8 Measurement of CVP in the abdominal inferior vena cava (IVC) via the FV avoids such complications and has previously been used to monitor both adults and children within intensive care units.2,9 The accuracy of From the Department of Cardiology, Papworth Hospital, Papworth Everard, Cambridgeshire, United Kingdom. Dr. Walsh’s address is: Papworth Hospital, Papworth Everard, Cambridgeshire CB3 8RE, United Kingdom. Manuscript received April 26, 1999; revised manuscript received and accepted September 21, 1999.

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©2000 by Excerpta Medica, Inc. All rights reserved. The American Journal of Cardiology Vol. 85 February 15, 2000

MD

such measurements in adults breathing normally, however, is unknown. This study measures right atrial pressure and compares it with venous pressure in the SVC, IVC, and FV to establish whether CVP can be accurately measured distant from the right atrium via the FV. •••

Sixty patients undergoing FV catheterization for right-sided heart studies or coronary angioplasty were assessed. Most were admitted from outpatients and no patient was critically ill requiring mechanical ventilation. Left ventricular function was considered impaired in 28 patients, as determined by left ventriculography, but no patient had evidence of decompensated heart failure at the time of study. All provided written informed consent and the study was approved by the local ethics committee. Following insertion of a femoral venous sheath (6/7Fr diameter), a multipurpose catheter (Cordis, MPA 2, length 110 cm, Roden, the Netherlands) was advanced into the FV. This catheter has side holes to avoid spurious pressure recordings from entrapment of the catheter tip. Under fluoroscopic guidance, the 0002-9149/00/$–see front matter PII S0002-9149(99)00787-0